Electric lamp



T. L. DENNIS.

BLBGTRIG LAMP.

170.247,177. Patented Sept. 20,1881.

ley] 12%? Vm W n .WH/Wb. zy www@ NITED STATES PATENT OFFICEe THOMAS L.DENNIS, OF BROOKLYN, NEW YORK.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 247,177, datedSeptember 20, 1881.

Application filed February 16, 1880. a l

ing kind, which shall possess a cheap and simple construction, dispensewith clock-work mechanism, and effect the feeding and separating ofthecarbons in a positive manner by the direct action of thecontrolling-magnet,'r

and in which, furthermore, the carbons may be renewed continuouslywithout discontinuing the light or in any way stopping the action of thelamp.

To these ends my invention consists in the" construction, operation, andcombination of i the various'parts, more fully hereinafter described,and then pointeduout in the claims.

lnthe annexed drawings, Figure lis a front elevation of my improvedlamp, and Fig. 2 is the heads a c', as seen best in Fig. 2. The

a central sectional side elevation thereof.

The frame of the lamp is of about the usual l form, consisting of twocircular heads, a a',

joined by upright bars b b, and between which the magnets c andregulating mechanism are mounted, and from which the upper carbon is -orfixed definite point, instead of at a varying point, the lower carbon ishence fed up by spring or weight in a tubular guide, f, fixed to thecross-bar e, the top of which is fitted with platinum points y y, whichbear upon the tip of the carbon near the base of the taper thereon,andpermit the gradual out-feed of the carbon as the consumption thereoftakes place in a well known manner, which will be readily understood.Now, this lower carbonis held ina short holderor tube, g, whichencircles or partly en` circles the carbon, and is pressed up by aspiralspring, h,- both of which are guided in and in-v closed by theguiding-tube f. rlhe carbon is clamped in the holder g by a screw, i, orsimilar device, which projects through and is guided in a slot on thefront of the guidingtube, while the lower end of the spring. rests onthe cap f', which is adjustable on the tube, to permit of regulating thetension ofthe spring, and is also perforated at the center to permit thefree insertion of the carbons. It will now be observed that thecarbon-holder g,'as well as the guide-tube f, is open at the bottom, sothat long before lthe first piece ot' carbon is exhausted the holder gmay be unclamped from it, pressed down, and a fresh carbon rod insertedclose up against the first, and the carbon being then clamped in theholder by a turn of the screw, the spring will continue to feed up bothpieces, as illustrated in Fig. 2. In this way, as will be perceived, thecarbons may be constantly renewed without ever stopping the light, andin the most simple manner, which constitutes a material advantage of myinvention.

The upper carbon is supported in a long tube, 7c, which is guided incentral bores through lower end of the tube extends close to themeeting-point ofthe carbons, and it is slit from this end to or aboutits middle, and this middle portion is reduced 'in thickness, so as todivide the lower portion of the tube into two very elasticspring-jawsdike those of a chuck, which are adapted toy grasp the carbonnear the point. Now, the armature l of the magnets c cis fixed to thiscarbon-tube k just above the head a, so that the tube is raised by theattraction ot' the armature and depressed'when the attraction ceases orweakens beyond a certain point.

The lower end of this carbon holding tube lo 'from the lower head, e,and is adjustable in a tubular neck, t', fixed to this head. l The lowerportion of this guide-tube is also slit, and is encircled by a collar,m, provided with ascrew, by which the mouth of the guide-tube, throughwhich the carbon-tube 7c projects, may-be contracted more or less. Now,the mouth. of the guide-tube t is fitted with a small roller,fn,"on eachside,which closely approaches the'car-A bon tube 7c, and the jaws .ofthe carbon :tube directlybelow the rollers are slightly diverged,and'also slightly taperedwith a downwardincrease, so that when the tubeis raised the jaws become closed by-contaet with the rollers n n, thusgrasping and holding the upper carbon at a point slightly separated fromthe lower carbon, while when the tube is depressed the jaws are relaxed,and the carbon is free to fall toward the lower carbon. The depressingor feeding movement of the carbon-tube 7c is effected when theattraction of the magnet c weakens, partly by the weight of the tube,and chiefly by the action of a spring-lever, 0, which acts in oppositionto the attraction of the magnet. rlhis leveris preferably of elbow form,and is fulcrumed at the bend, its long arm being connected by a springto an adjustable tension -screw,p, on the upright b, while its shortarm, which is forked, straddles the carbon-tube near the top, and restsupon an ad* justable collar, r, fixed thereon. Now, more or less tensionmay be put upon the lever by adjusting the spring tension-screw p tomake the lever resist the magnet more or less, according torequirements; but an adjustment of much greater range and accuracy isobtained by changing the fulcruni-point of the lever, which, accordingto myinvention, is made adjustable-.that is,-this lever is mounted atthe bend on the end of the adjustable screw s, which is screwed throughthe upright b, and its tip, which is rounded, enters a rounded cavity inthe bend of the lever, forming a balland-socket fulcrum for the lever torock upon. It will now be seen that by adjusting the screw s the leverwill be moved to or from the carbon-tube, its forked short arm ridingover the collar r thereon, thus changing the fulerumpoint, or, ineffect, shortening or lengthening the short arm relatively to thelongarm. The tension or downward pressure ot' the lever upon the carbon tubecan thus be regulated in an instant with great nieety and within a greatrange, so as to compensate for any strength oi' attraction, which, ofcourse, represents the strength of current. In this way the lamp, Awhenset up, may be adjusted perfectly to suit 4the strength of current withwhich it may be supplied, so that the feeding and separating movement ofthe carbon tube will always be etfected with sensitiveness andcertainty.

It will now be observed that the upper-car- .bon tube is open from endto end, and that when the armature and the tube is depressed thegrasping end of the tube will become relaxed, so that a carbon rod maybe dropped freely into the tube from the top, and, descending throughthe same, its lower end will finally pass through the graspingmouth ofthe tube and fall into contact with the lower carbon. Now,.when thecurrent circulates the armature will be attracted, and, raising thetube, will contract the same upon the carbon, thus grasping the carbon,and at the same time raising it slightly from the lower carbon, thuseffecting the separation to the required extenta The carbon and its tubewill be then held suspended by the attraction ofthe magnet,

and will vibrate up or down slightly, accord ing as the current weakensor strengthens by the change in the points. Then the carbon, however,becomes consumed enough to weaken the current below the tension of thedepress ing or compensating lever o, the tube will be at once depressed,thus losing its grasp on the carbon, which will at once fall toward thelower carbon; but as the carbons approach, however, the current at oncestrengthens and increases the attraction, which raises the tube, andthus again grasps the carbon and separates it the proper distance fromthe lower carbon.

By this construction it will be observed that the feeding and separatingof the carbons is effected in a very perfect manner, and with verylittle mechanism, and that of a simple kind, and, moreover, theilluminating-point is always kept at the same focus.

It will also be seen that before the first carbon is consumed in theupper tube another carbon may be inserted above it, to follow down the,former one, thus rendering the action ofthe lamp continuous, andenabling the carbons to be renewed for any length of time withoutinterrupting the light.

It may now be observed that in this lamp one otthe carbons is constantlyfed up against fixed refractory points in a hxed holder, while the othercarbon is held in a movable holder actuated by regulating mechanismcontrolled by the electric current, which causes this can bon toapproach to or recede from the'other carbon as the current weakens orstrengthens, or as the form ot' the carbon points changes. Hence by thismeas, as may be appreciated, a more perfect focus is maintained and abetter control of the carbons and regulation ot' the light is securedthan where both carbons are fed up against refractory points at fixeddistances, for in the latter case the carbons often burn oft' with suchirregularity as to cause on the one hand a too far separation, or on theother hand a too close approach, which is et't'ectually obviated bycontrolling one carbon by the currentand forcing the other against fixedrefractory points.

By adjusting the collar m on the gnide-tube t and the tube t in the neckt, the carbon-tube k may be made to grasp the carbon sooner or later inits rising movement, as will be readily understood.

Instead of a magnet and movable armature, atixed solenoid coil withmovable cores attached to the carbon-tube may, ot' course, besubstituted.

The current enters the lamp through the binder -ion the head a', andthence descends through the upper-carbon tube and carbon to the lowerone, from which it passes to the rod d, and from thence through themagnetic coils, and ott' by the insulated binder on the head a.

Another feature of my invention consists in embodying in and providingthe lamp with IOO TIO

a switch controlling the internal circuit of the lamp, and arranged uponthe exterior of the lamp in an accessible position for manipulation bythe hand, so that when any emergency requires it the circuit may bebroken or closed at the lamp itself without requiring to detach wires orto go to the machine or switch-board.

I prefer to arrange this switch, as shown at u in the drawings, upon thecross-bar e, so as to connect the lower-carbon guide-tube with the rod tof the lamp-frame; and it preferably consists of a spring-arm fixed tothe rod and arranged to spring` over and catch under a hooked projectionon the lower-carbon guide and by manipulating which it will be observedthat the internal circuit of the lamp may be closed or broken, as may berequired. I also prefer to arrange this switch so as to be trippedby theterminal movement of the travelin g carbon-holder before the carbonbecomes entirely exhausted, by simply providing the holder g with aprojecting pin, v, adapted to pass through a hole in the cross-bar e andstrike againstand trip the switch, thusbreaking the circuit. This, aswill be observed, acts as a safety device, to prevent by any chance theconsumption of the platinum points y, which might becaused by the toonear approach of the upper carbon in case the lower carbon should becomeentirely exhausted, but which is fully guarded againsthy the describeddevice.

What I claim as my invention is- I. The combination, in an electriclamp,of a movable carbon-holder having one end formed as a clutch togripe or release the carbon, in combination with a fixed device, t,encircling,

or partly encircling, the said clutch, and. ar-

ranged to contract the clutch upon the carbon when moved in onedirection, and permit the clutch to relax when moved in the oppositedirect-ion, substantially as herein shown and described.

2. The combination, in au electric lamp, of a controlling-magnet, and aseparating and feeding carbon-holder actuated by said magnet, with atension-lever opposing and compensating the action of the magnet,mounted on an adjustable fnlcrum, and having one arm resting on thecarbon-tube, and its other end .connected to a spring, whereby theleverage against the magnet may be increased or decreased, substantiallyas and for the purpose set forth.

3. In an electric lamp, acircuit breaking and closing switch embodiedwithin the lamp, and forming part of the internal circuit thereof,arranged upon the exterior of the lamp in an accessible position formanipulation by the hand, in combination with means, substantially asdescribed, to automatically break the circuit when the carbon isexhausted, substantially as and for the purpose specified.

4.. An electric lamp constructed with a circuit breaking and closingswitch, forming part of the internal circuit thereof, with a movableelectrode or carbon or carbon-feeder arranged to trip the said switchand break the circuit by its terminal movement, substantially as and forthe purpose set forth.

5. The combination, in an electriclamp, with a regulating-magnet, of apendent carbonholdin g tube open throughout, adapted to permit thegravitation of the carbon through the same, having its lower end formedto grasp or release the carbon by the action of the magnet, and itsouter end open to permit the free insertion of additional carbons tofollow the preceding one withoutinterrupting the action of the same,substantially as shown and described.

6. In an electric lamp, a traveling carbon clamp or holder,substantially `as set forth, adapted to be securely fastened to thecarbon and travel with it at the same rate as it burns, and open at thebottom to permit the free insertion of additional carbons to follow upthe preceding one without interfering with the same, in combination withdevices, substantially as described, to impel and guide the holder, asand for the purpose specified.

7. An electric lamp in which the luminous end of the electrode or carbonis constantly pressed or fed against refractory points or fixed stops,provided with the traveling carbonholder, impelled and guided bysuitableineans, and adapted to impel and travel with the carbon in acontinuous manner the full length of the same, or thereabout, secured tothe carbon by a lateral grasp, and open at the outer end to permit theinsertion of an additional carbon to follow up the preceding one withoutinter rupting the same, substantially as herein set forth.

THOMAS L. DENNIS. Witnesses:

GHAs. M. HIGGINS,

EDWARD H. WALEs.

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